Caroline Wozniacki's preparations for the US Open got off to the worst possible start as she was beaten 6-4, 6-2 by Varvara Lepchenko in the second round of the Bank of the West Classic on Thursday.
Lepchenko proved unstoppable in the encounter, as she won 82 percent of points on her first serve and saved the only break point on her serve in the first set, while breaking Wozniacki once to take the set 6-1.
The American raced out to a 4-1 lead in the second set and never looked back, putting intense pressure on the Wozniacki serve which the Dane win just seven of 19 points on her own serve. Lepchenko held firm and served out the set to take the match 6-4, 6-2 in an hour and 33 minutes.
That would be the lone upset of the day though, as second seed Agnieszka Radwanska beat Japanese qualifier Misaki Doi 1-6, 6-2, 6-0, while fourth seed Karolina Pliskova defeated Kimiko Date-Krumm 7-5, 6-2.
Fifth seed Angelique Kerber, who lost last year's final to Serena Williams, downed Ana Konjuh 6-4, 6-3.